Graphic depiction of the amount of sunlight above and underneath the Arctic sea ice. The growing coverage of the ice by darker meltponds increases the share of sunlight [that] passes the sea ice. That means, the space underneath the ice becomes brighter and warmer. Furthermore less sunlight is refleced back into the atmosphere. Graphic: Alfred Wegener

The Arctic sea ice has not only declined over the past decade but has also become distinctly thinner and younger. Researchers are now observing mainly thin, first-year ice floes which are extensively covered with melt ponds in the summer months where once metre-thick, multi-year ice used to float. Sea ice physicists at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have now measured the light transmission through the Arctic sea ice for the first time on a large scale, enabling them to quantify consequences of this change. They come to the conclusion that in places where melt water collects on the ice, far more sunlight and therefore energy is able to penetrate the ice than is the case for white ice without ponds. The consequence is that the ice is absorbing more solar heat, is melting faster, and more light is available for the ecosystems in and below the ice. The researchers have now published these new findings in the scientific journal Geophysical Research Letters.

Melt ponds count among the favourite motifs for ice and landscape photographers in the Arctic. They are captured glistening in a seductive Caribbean sea blue or dark as a stormy sea on the ice floe. “Their colour depends entirely on how thick the remaining ice below the melt pond is and the extent to which the dark ocean beneath can be seen through this ice. Melt ponds on thicker ice tend to be turquoise and those on thin ice dark blue to black”, explains Dr. Marcel Nicolaus, sea ice physicist and melt pond expert at the Alfred Wegener Institute.

In recent years he and his team have observed a strikingly large number of melt ponds during summer expeditions to the central Arctic. Virtually half of the one-year ice was covered with melt ponds. Scientists attribute this observation to climate change. “The ice cover of the Arctic Ocean has been undergoing fundamental change for some years. Thick, multi-year ice is virtually nowhere to be found any more. Instead, more than 50 per cent of the ice cover now consists of thin one-year ice on which the melt water is particularly widespread. The decisive aspect here is the smoother surface of this young ice, permitting the melt water to spread over large areas and form a network of many individual melt ponds”, explains Marcel Nicolaus. By contrast, the older ice has a rougher surface which has been formed over the years by the constant motion of the floe and innumerable collisions. Far fewer and smaller ponds formed on this uneven surface which were, however, considerably deeper than the flat ponds on the younger ice.

The growing number of “windows to the ocean”, as melt ponds are also referred to, gave rise to a fundamental research question for Marcel Nicolaus: to what extent do the melt ponds and the thinning ice alter the amount of light beneath the sea ice? After all, the light in the sea – as on the land – constitutes the main energy source for photosynthesis. Without sunlight neither algae nor plants grow. Marcel Nicolaus: “We knew that an ice floe with a thick and fresh layer of snow reflects between 85 and 90 per cent of sunlight and permits only little light through to the ocean. In contrast, we could assume that in summer, when the snow on the ice has melted and the sea ice is covered with melt ponds, considerably more light penetrates through the ice.”

To find out the extent to which Arctic sea ice permits the penetration of the sun’s rays and how large the influence of the melt ponds is on this permeability, the AWI sea ice physicists equipped a remotely operated underwater vehicle (ROV “Alfred”) with radiation sensors and cameras. In the summer of 2011 during an Arctic expedition of the research ice breaker POLARSTERN, they sent this robot to several stations directly under the ice. During its underwater deployments, the device recorded how much solar energy penetrated the ice at a total of 6000 individual points all with different ice properties!

A unique data set was obtained in this way, the results of which are of great interest. Marcel Nicolaus explains: “The young thin ice with the many melt ponds does not just permit three times as much light to pass through than older ice. It also absorbs 50 per cent more solar radiation. This conversely means that this thin ice covered by melt ponds reflects considerably fewer sun rays than the thick ice. Its reflection rate is just 37 per cent. The young ice also absorbs more solar energy, which causes more melt. The ice melts from inside out to a certain extent,” says Marcel Nicolaus.

What might happen in the future considering these new findings? Marcel Nicolaus: “We assume that in future climate change will permit more sunlight to reach the Arctic Ocean – and particularly also that part of the ocean which is still covered by sea ice in summer. The reason: the greater the share of one-year ice in the sea ice cover, the more melt ponds will form and the larger they will be. This will also lead to a decreasing surface albedo (reflectivity) and transmission into the ice and ocean will increase. The sea ice will become more porous, more sunlight will penetrate the ice floes, and more heat will be absorbed by the ice. This is a development which will further accelerate the melting of the entire sea ice area.” However, at the same time the organisms in and beneath the ice will have more light available to them in future. Whether and how they will cope with the new brightness is currently being investigated in cooperation with biologists.

Photo, taken by the ROV (Remotely Operated Vehicle) during its dive through deformed sea ice. The marker bars are one meter long. In the background one can see that more sunlight passes the sea ice, because the ice is covered by meltponds. The numbers and symbols, which are faded in, tell the direction and position of the ROV. They are needed by the pilot to steer the underwater roboter. Photo: Alfred Wegener

Arctic sea ice is melting much, much faster than even the best climate models had projected (actual observations in red). The reason is most likely unmodeled amplifying feedbacks. The image (from Climate Crocks via Arctic Sea Ice Blog) comes from a 2007 GRL research paper by Stroeve et al.

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With almost every new discovery or increase in available data relating to the Arctic, we edge ever closer to a terrifying conclusion: The Arctic region (including Greenland) was/is in a far more precarious balance than we suspected. It won’t take repeated, huge kicks to send the system wobbling into another equilibrium state; it’s increasingly clear that a minor nudge of just a couple of degrees is all it takes to set feedbacks in motion — albedo plus unlocking those immense carbon stores in hydrates and permafrost.

Look at the paleo temperature record, and we see a persistent pattern of a saw-tooth curve: Very rapid rise and slower decline. Currently, we are almost certainly learning exactly which mechanisms cause those rapids temperature increases, and it’s anything but good news.

Yes and, of course, the x-factor that I do not believe scientists can truly quantify is the unprecedented speed at which the warming and GHG build-up is occurring. There are many studies comparing Arctic and Greenland Ice melt to, let’s say, that of the Eemian period which was at least 1C warmer than we are today. BUT- how indicative are those studies?…how to compare a so-far warmer Eemian with a present situation in which the warming is occurring in decades rather than multi-centuries and Millenia? (and one in which the major forcing is not increased insolation and orbital changes but is our build=up of GHGs) I guess we are going to find out!

The Arctic is gone! The combination of solar insolation having increased absorption in open water and warm water rushing in from the Atlantic insure the end for the ice cap. Whether it takes two years or five for this to happen is of minor relevance. The point is, it will happen, and there are no credible plans to stop it. Even the geoengineering schemes proposed focus on reducing solar insolation, but the warm Atlantic water is more than adequate to eliminate the ice cap. The subsequent heating of the water will raise its temperature and put real stress on the clathrates. We are witnessing the end of our civilization, with zero plans on the books or actions to stop it.

It seems so obvious that losing the ice cap will be immediately catastrophic for the climate, and that it’s going fast, that one has to wonder what conversations are happening at the highest levels. It’s really getting to be sci-fi/ Dr. Strangelove time.

On the other hand, when I try to talk to anyone about this, they shut down. They feel they can’t control it. But we could do something if we had the leadership. Inhofe and Obama from the Oval Office, emissaries to China and the other G8 nations. A UN summit.

Yes, that would provoke the reactionaries, the America-Firsters, the Black-Helicopter-Blue-Helmet-Fearing-2nd-Amendment-Solution people. But if the ice cap goes, we have to face that down anyway. The post-ice-out social and political chaos will be cataclysmic.

“that one has to wonder what conversations are happening at the highest levels.”

Given that the ‘black’ community must be studying this in detail, with unlimited funds, one wonders why we hear nothing. They understand better than anyone the catastrophe we face. I believe the only remaining hope is the imposition of involuntary mandates by those who control the physical levers of power, and their counterparts in other countries. I would have expected some action by now, since they have small grandchildren and great-grandchildren they would want to protect. But, the occupants of these vaunted positions all do quite well financially, and they may not want to give up the benefits that would accompany strict rationing nad other mandates. If left to voluntary means, we’ll burn every remaining drop of fossil fuels.

The hate campaign of the Right to intimidate and slander climate scientists does seem to have worked. I’m only a lay-person, but to my eyes the reports of rapid change in the northern cryosphere have been markedly more worrying than the ‘scientific consensus’ for years. I’m not at all surprised by the rapidly unfolding disaster, yet mainstream climate science still seems to be downplaying, while, at the same time, the denialist dulloids are still screeching ‘Alarmism’. Why are scientists still so reticent, when this calamity, and the huge quantities of added heat that the planet will absorb now that the albedo has comprehensively ‘flipped’, surely signal a rapidly unfolding catastrophe? Most of the reports I see from establishment climate science still use the soft denialism of speaking of bad consequences in ‘2050’ or, even more ludicrously ‘2100’. We’re going to be in deep doo-doo by 2020, and by 2100, at this rate….well I’ll leave that up to your imagination.

It’s not the deniers Mulga, it’s a problem with the reductionist science all the mainstream climatologists use. The system is firstly analyzed variable by variable (part) and the best projections of each fed into a model that attempts to build them all back, Humpty Dumpty like, into a system. To the best of my knowledge, they cannot build in all the various interactions of the parts so all model-based predictions are conservative approximations of what actually happens when a critical change occurs in a system. I have given up hope that a genuinely systemic approach or maths will be used so we will continue to be ‘surprised’ by the speed of change, ME

I haven’t posted in quite a while because I’ve gotten so discouraged. But I have to comment that Merrelyn has nailed it perfectly. The climate system is obviously a non-linear system, and such systems tend to lurch from one semi-stable state to another because of all the non-linear feedback mechanisms that come into play in any complex system. We’re just seeing the beginnings of such a lurch that will continue to blow most model predictions out of the water since nobody really knows how to model non-linear changes in any meaningful way, though some in the systems and complexity communities are probably trying. So, I continue to be discouraged that anything can or will be done to avert the chaos that’s coming.

Systemic thinking can only take hold as fast as we start to doubt capitalism as a desirable economic model, for the reason that systems-based thinking puts the capitalism’s society-busting fatal defect right in our faces… e.g., the mandatory requirement for nonstop economic growth, forever.

Systems-based thinking tells us that no matter how many “wedges” we deploy, all of those environmental gains of whatever nature will eventually be erased by the inexorable rise in the “bad consequences” of even the greenest but forever-growing economy.

And so, global warming is just a symptom of our society’s philosophic outlook…. in which reductionist thinking is king, because it drives the engines that seek nonstop growth, the heart of capitalism. Even if we solve AGW, some other just-as-society-busting application of basic ecology will bring us down, if we try to keep growing, forever.

Obama will only tackle AGW if it does not come at the expense of growth and jobs, and so even if he kicks it into gear, he will still be tackling a symptom, while perpetuating the root cause.

Science has evolved into the creation of research empires. To generate ‘leading-edge’ science, and reap the rewards, one needs graduate students, travel funds, equipment, facilities, etc. This requires a steady stream of copious funding. The main source of research funding is the government. In order to keep getting these funds, the researchers are forced to do what the government sponsors want. What they don’t want is to get the larger public over-concerned or over-wrought. Then, they may want retribution, and the politicians are an easy target. So, the problem is continually downplayed, and I believe it is not by accident.

Change is alot of work. The Earth is working harder with more energy from burn.
Certainly to redo all those maping ways with the change of the Arctic area each year as the Arctic shrinks would be trouble to keep a map accurate for even one year. My guess though is that the ones who decided to call it the Arctic had some things in mind to quantify the area. Such as the near impossibility of shipping and other forms of commerce. Well that peramiter has changed. That there was no need of ownership therefor, that seems to be changeing as well.
Won’t some one help me with the other perameters that made for the boundries of the Arctic area. They must have had reasons to call the area such and such. If those reasons are no lnger in force it does seem rather willy nilly.

Excuse me for being a perpetually optimistic inventor, but it’s possible that an aircraft dropping little rocks of sea salt all over the first year ice could cause holes in the ice so that the melt ponds could drain out. This would change the ice’s albedo. It would be really nice if some scientist or gifted grad student with smarts and ambition — ok, a shiftless bum of a high school science student will probably work too — would run a little experiment outside in this winter weather or in a freezer and prove the concept out for a science fair.

Yes, there’s a complaint that a standard aircraft in 2013 is fossil fuel intensive. That’s entirely the current aircraft industry’s fault. One aircraft has crossed the English Channel on bicycle power alone, so aircraft energy efficiency improvements can certainly be made if you want to lower the ice’s albedo without killing the climate.

Not meaning to belittle your thought at all: but it made me smile because an image of a cargo plane full of salt pellets being powered by 10 or so furiously peddling away beneath the body of the airplane appeared to me- actually that would be a very beautiful thing (though I imagine that is not at all how a bicycled powered aircraft actually works).

Is this a satire? I’d point out that broadcast salt melts ice indiscriminately, not just at the bottom of melt ponds (where it would probably dissolve in the water before reaching the bottom), but I hate showing myself too dense to pick up on a joke.

Since you want a more focused rock pellet, all right then, we shape a salt pellet in the shape of a cylinder with one open end. We put a slightly biodegradable jacket around the salt pellet and we build an air bubble at the contained end of the salt pellet. On the ice, the pellet melts itself down until its open salty end is pointing downward.

All of the salt rock’s melting power then goes into driving itself downward into and through the ice, digging a hole. Once the device pokes itself out the bottom of the ice it sinks to the bottom of the ocean. No indiscriminate ice melting, just one hole.

Find a big piece of rock salt and an ice cube. Put the rock salt on the ice cube at various temperatures and see if it digs a hole straight through the middle of the cube. For a larger experiment, freeze a thicker ice cube in the freezer and use a larger piece of rock salt.

You could start with a back of the envelope computation of how much salt you’d need. You are trying to cover a few million KMsquared of area, and need a however big salt grain every so far. My guess is you’d find you need a gazillion planes.

I’ll take a guess that a 1 gram salt rock goes through 1 inch of ice, and that the ice is an average of 40 inches thick. So a 40 gram salt rock punches a drip hole through a 40 inch ice pack.

We might want drain holes punched every 100 feet, in a grid. This creates 50 x 50 such rocks per square mile, or 100 kilograms per square mile. We would want to protect perhaps 2 million square miles of core ice pack. That’s 200,000 metric tons of salt.

Lifting 200,000 metric tons a year, 20 tons per flight, would require 10,000 flights. If you could get 5 flights every 24 hours over a 300 day period, that’s 67 aircraft. You’d need to hire multiple crews, of course.

One remaining problem is scattering the rocks. We might be able to craft a small paper sail to each rock so that when we drop the rocks from 10,000 feet, they tend to sail off to the left and right of the drop path.

The ice is gone, or is going be gone within five years, and the world’s climate is going to shift — correction, is already shifting — into a new, unstable state. Nobody knows exactly where this is going, but, among other things, it will bring a lot more carbon from natural feedbacks into the atmosphere.

All geoengineering will do us muck things up worse. Our only hope for slowing down climate destabilization and, with a good deal of luck, keeping us from getting into a runaway warming situation, is to reduce our own carbon output to near zero ASAP.

No, but I can be brief. A light colored parking lot, specifically in areas of the country without road ice, reflects more heat back into space than a blacktopped lot. So does a light colored road or a light colored breakdown lane. So does a white roof.

Cutting a fire lane in a forest so that a wildfire doesn’t torch your house is an unnatural geoengineering activity. It prevents perfectly normal fires from sweeping through. Nevertheless, you’ll cut that fire lane and not feel the least bit guilty about it.

This one – white roofs – I like. There are some jurisdictions where white roofs are forbidden! (By some Home Owner Associations in the US, common private collectives the main function of which are to enforce aesthetic standards.) One person posted (here, I think) that he lost his home insurance when he painted his roof white. These can be easily addressed by state laws. Homeowners and businesses would typically save money in cooling costs by doing this.

And think how much nicer it would be when the power goes out for weeks at a time…

I don’t think you understand how catastrophic and lethal these events are. Nobody looks ‘fondly’ on 2010-11 and in some places such as Bundaberg, the situation is now worse. Vast torrents, metres high ripping through towns at 40 knots will never be remembered with anything approaching affection, ME

This is what happens at 0.8 C. My relatives had their house destroyed along the New Jersey coast with Hurricane Sandy. I understand the disaster. My point was consider what will happen when the temperature increase doubles or triples. Remember, Sandy was ‘only’ a Cat 1 hurricane when it came ashore in NJ/NY. What will happen when storms of this extent come ashore as Cat 3s or Cat 4s? You think too literally; you need to think more metaphorically.

Where’s the point the citizenry grabs a hold of the reigns on this issue – Australia seems to be the worst hit (and forecast to be the worst hit going forward) – short of the arctic and antarctic region.

Our thoughts are with you folks down there Mulga and M.E.. It’s going to be a tough decade.

Thanks Sasparilla. There are a lot of people trying very hard and there have been a couple of recent sucessess like stopping the Supertrawler and a half decent plan to save the Murray-Darling system. Stopping coal mining and fracking is extremely difficult but more are making the connections and getting pretty stroppy about it so ‘it’s on’, ME

I don’t view living in a fantasy world as optimism. The actions required to ward off the worst of climate change are massive and immediate. We have not only been doing nothing for the past thirty years, we in fact have been digging the hole deeper as fast as we can. There is zero evidence this will change; the BP energy outlook for 2030 has fossil fuels increasing by 30% over 2010. That’s based upon what’s on the books world-wide. I see zero evidence of interest in making the changes required, at both the decision-maker level and the people I know. All I’m doing is stating that fact, and if you have any real evidence to the contrary, I’d be glad to hear it.

We need three actions in parallel, starting yesterday: eliminate fossil fuel combustion ASAP; initiate rapid carbon recovery ASAP; perform low-risk geoengineering ASAP to ‘quench’ the positive feedback mechanisms that have been triggered. That’s what we need. I would wager that what we’ll get is something very close to BP’s energy outlook for 2030, which shows an increase of 30% for fossil fuels over 2010.

Superman1 you’ve laid out, very succinctly, exactly what we need to do. I wish there was a likelihood of that happening in the next 5 years – and I wish the odds of it happening during the next 15 weren’t so low (depending on climate change disasters here in the U.S. causing voters to override the fossil fuel industry control in D.C. on a monumental scale never seen before – since we’ll need WW2 scale action).

As you pointed out, it’s becoming increasingly likely we’ll just keep the CO2 pedal down the whole way over the cliff – fulfilling BP’s hopes…I hope that’s not the case, but the odds keep shifting that way as time marches on.

I view the real problem as addiction by the energy consumer to a high usage intensity lifestyle enabled by unlimited availability of cheap fossil fuel. While the fossil fuel industry aids, abets, and exploits this addiction, they are not the central problem. That’s why it is so difficult to solve; addicts by and large don’t like to give up their addictions unless absolutely necessary. Smokers, drinkers, and other addicts will surender life itself rather than surrender their addictions. That’s where the overwhelming bulk of the population is on fossil fuel use, and why I see negligible impetus for change.

I have always had the highest respect for EERE people, and worked with them extensively. But, I disagree with you on this one. The ‘public’ supports climate action in words only. When it comes to the necessary belt-tightening, they’re nowhere to be found.

Who is calling for belt-tightening? Not bloody many people. So why should masses of folks do it voluntarily? It wouldn’t solve the problem without federal legislation anyway. So you can’t fault people for not doing it.

I disagree with both of you. The public wants climate action, sure, that I accept.

However, our society is nonetheless fatally addicted to something other than fossil fuels…. nonstop economic growth, forever (aka the engine of capitalism).

Whatever gains green tech provides will be wiped out by the ecological cost of nonstop, perpetual, economic growth.

Me? I’m all for Pearl Harbor-esque deployment of the wedges, but only with full knowledge that this would only be the first sortie in a much broader war. We MUST learn to be happy WITHOUT economic growth, or wedge-deployment is pointless in the long run.

Mark E, it’s not the people who just toddle off to whatever jobs they can get, come home and try to make their lives as least miserable as they can manage. It’s the elites with the growth bee in their bonnets, ME

You may engage in elite-bashing if you like, but IMO that’s an uninformed response. Workers quite naturally want happiness and security. When you take growth away in a capitalist economy they have neither…. and they are *acutely* aware of the connection. Do those workers then toddle to the polls to demand steady-growth economics? NO! They elect whoever they think will re-establish growth.

I don’t pretend to know what democratic steady-state economics looks like, or how it works. I mean, who is? Do we ever really talk about it?

But I am dead certain that all levels of capitalist society – not just the elites – are addicted to a status quo that is ultimately fatal to our civilization. Example: know anyone who has tried to sell a house when the economy has been stagnant, and then oozed with relief when it suddently started to grow again? “Thank god! Now we’ll be able to find a buyer!”

It ain’t just the elites who have this particular addiction. Simply talking about the need to look for alternatives is the first step to breaking it.

Mark E, I usually don’t comment on matters about which I am uninformed but I missed the point at which the US became a workers’ paradise where workers discuss esoteric economic theories and participate in policy making at the highest levels, ME

Mark E, I usually don’t comment on matters about which I am uninformed but I missed the point at which the US became a workers’ paradise where workers discuss esoteric economic theories and participate in policy making at the highest levels, ME

That we engage in activities that are contrary to the formation of a liveable planet is evident. So isn’t it right to say we are contary to nature? As yet it seems fanticy to think that there are other laws of physics that will be revealed which show us to be acting in the best interests of children. But of the other hand some psyche docs think that encouragement to an improvement is superior than telling a crazy person the truth. Just saying.

M.E., we are not communicating well. My point is that workers are brainlessly programmed to be blind to their addiction to economic growth. They don’t have to TALK about the matter openly, they only have to be persuaded to pull the boat according to the capitalist navigator’s orders. What else explains how the candidates uniformly campaign on the theme of how THEY will bring about growth more than the next guy? (Male gender intentional)

I think we agree that this is how the elites want it to be. The solution is to make the uninformed aware that they are uninformed. See

In my view, the goal should be to make the workers aware they have NOT been thinking about the ecological underpinnings of the mythology on which their lives are precariously balanced.

In other words, to move them from “He who knows not and knows not he knows not” group, and into the “He who knows not and KNOWS he knows not” group. If we can do that, the rest will take care of itself, or so the Tao Te Ching seems to suggest.

In any case, whether it is all the elites fault without help from the workers, or it is the workers fault for letting them do what they do, or whether it is EVERYONES fault according to their station in life, I think we agree that systems-based thinking leads inexorably to one conclusion:

We can deploy every possible climate wedge, but if capitalism tryies to keep growing the economy nonstop – forever – the ecological toll of that growth will eventually erase all the gains of every deployed wedge.

In sum: do you disagree that wedge-deployment is pointless without tackling our addiction to nonstop – forever – economic growth?

Mark E, we agree that there are elites and they make policy. I don’t agree that workers are brainlessly programmed because when they are offered a choice, they usually choose the most adaptive option. I certainly do not agree that fossil fuel usage or belief in the necessity of growth is an addiction, ME

Raul, there is nothing “unnatural” about a species exceeding its carrying capacity. Happens all the time. The only unusual thing about our species and the current era is the duration of time prior to population collapse. All of the basic, e.g. “natural” principles still apply.

Philip – you write:
“All geoengineering will do us muck things up worse. Our only hope for slowing down climate destabilization and, with a good deal of luck, keeping us from getting into a runaway warming situation, is to reduce our own carbon output to near zero ASAP.”

Your generalized rejection of geo-engineering is not supportable. How for instance does all my tree planting over the years ‘muck things up’ ?

That rejection directly obstructs the essential RD&D of the most benign techniques, as well as discouraging the negotiation of the requisite UN governance and collective decision making. The upshot of such obstructionism is that we’re drifting towards the emergency imposition of the available, very cheap and very dirty stratospheric sulfate aerosols option to halt ruinously destabilizing global crop failures.

Your hope of avoiding the feedbacks becoming self-reinforcing by cutting global emissions is patently groundless. As a best case we could aim for near-zero global CO2e output by 2050 (way beyond the Cancun pledges) but this neither avoids the onset of global crop failures (likely in the 2020s) nor does it end the warming in 2050. Not only is there the 30yr timelag giving continuous warming till around 2080, but also there is the loss of the cooling sulfate parasol with the end of our fossil fuel burning.

In 2010 the most advanced feedback, albedo loss due to cryosphere decline, was reported in Geophysical Research Letters to be already imposing a major forcing, which the lead author stated was equivalent to around 30% of anthro-CO2 output. Five other major feedbacks are also widely observed to be accelerating, and a sixth (methyl clathrates) may well have begun to do so.

Allowing these accelerating interactive feedbacks another 67 years of intensifying anthropogenic warming before 2080 is a pretty certain recipe for driving them to a self-reinforcing condition, both indirectly, via interaction of the timelagged warming they are each generating, and directly, through immediate interactive effects such as the present loss of sea-ice sending warming airs over 1500kms of arctic permafrost.

Therefore it seems that your prejudice against geo-enginneering is not only deeply imprudent and a denial of the seriousness of the climate threat, it is also directly counter-productive for the benign goals that I’ve no doubt we share.

Seems like the consensus (folks using the “this is what we’ve seen so far” method of predicting how soon they’ll go away) is that we’ll loose the summer arctic ice before the end of the decade with some folks saying less than 5 years.

Unfortunately none of the models have been able to match what we’ve seen (by decades) on the ice melt, so reality is way ahead of what the models say and those are still saying stuff like 2030.

Warmer Arctic will cause more severe droughts, so the food crisis and Worldwide wake-up (though likely too late to save the majority of World species, inc human). We’ll probably witness the game-change by 2020.